Spray gun nozzle for spraying buffing compounds



NOV. 10, L w. SMITH Lesh'e W. Smit/L Patented Nov. 10, 1953 UNITED STATES PATENT OFFICE SPRAY GUN NOZZLE FOR `SPRAYING BUFFING COMPOUNDS 3 Claims.

This invention relates to a spray gun and more particularly to a nozzle for a spray gun which will better resist the abrasive action of grit and the like contained in compounds.

In the use of so-called automatic spray guns for spraying grit containing materials, such as buiing compounds, it has been found that the metallic parts of the nozzle, such as a needle valve when one is used, wear out very rapidly due to the high pressure that are employed in the ejection of the material.

In such guns, as is well known, the material is forcibly discharged from a central passageway under the propelling or aspirating effect of high velocity air jets focused in the locale of the material discharge orifice.

It is an object of this invention to provide a spray gun nozzle structure or fitting which is so arranged and is of such material that it will better resist the abrading action of the material being discharged therethrough, and will stand up for long periods of time without requiring frequent replacement of parts as is true in the use of the conventional spray gun as noted above.

Another object of this invention is to provide a nozzle with a fluid discharge passage made of resilient or rubber-like material and which can be readily adjusted to vary the rate of flow of fluid through the same.

In accordance with the general features of this v invention there is provided in a spray nozzle a housing having an elongated tubular passage, a yieldable rubber-like tube snugly fitted in the passage with one end positioned to discharge material therefrom, and a material supply passageway in the housing communicating with the other end of the tube.

Another feature relates to the provision in the aforesaid nozzle structure of a movable valve cooperable with the other end of the rubber tube v to open and close its communication with the material supply passageway.

Yet another feature of the invention relates to the provision of means in the nozzle housing for manually adjusting its bearing against the rubber tube and adapted to displace a portion of the tube to vary the cross-section of the bore thereof and thereby to vary the rate of discharge of material through the tube.

Other objects and features of this invention will more fully apear from the following detailed description taken in connection with the accompanying drawing which illustrates several embodiments thereof, and in which Figure 1 is a side view partly in section of an automatic spray gun embodying a nozzle assembly of my invention;

Figure 2 is an enlarged cross-sectional view through a detachable sleeve comprising a part of the gun housing and which defines the nozzle passageway; and

Figure 3 is an enlarged elevation of a rubber tting or sleeve insertable in the housing sleeve shown in Figure 2 to dene the material discharge passageway in the nozzle assembly.

As shown on the drawing:

The reference character 9 designates generally an automatic spray gun which is of a conventional construction with the exception of my novel nozzle mechanism which I shall hereinafter describe. The gun 9 includes a housing designated generally by the reference character l0 which may be made up of one or more pieces in accordance with the particular desires of the manufacturer. The housing I0 includes a threaded nipple I I for connection to a fluid supply under pressure, such as air, which is adapted to be used in the aspirating and projection of the material from the gun. A similar threaded nipple I2 is provided with a connection to the air supply for delivering air under pressure for actuating a piston or diaphragm (not shown) in the portion I3 of the housing. Such air pressure supplied through the nipple I2, as is well known in the gun art, is employed to open and close the valve at ythe nozzle which is actuated through the movable rod I4 and which in the usual gun is called the needle valve rod.

In accordance with the features of this invention I have shortened this rod I4 and provided it with a conical valve head I5 cooperable in a novel way with a yieldable tube 20 to be described hereinafter. A suitable packing gland assembly I6 is provided around the rod I4.

Also, the forward end of the housing I0 is provided with a material supply passageway I'I for connection to a hose line through which material to be projected is delivered. For illustration, if the gun is to be used in spraying bufling compound, such compound would be delivered through the passageway Il to the area of the valve head I5.

The housing lIII has a detachable extension I8 which is threaded into the housing so as to be detachable as well as adjustable with reference thereto. This metallic sleeve I8 is adapted to have secured to it in the usual way an air nozzle assembly I9 which is of conventional or standard construction in nozzles available on the market.

The rubber-like tube of my invention comprises a liner for the metal sleeve I8 and is adapted to be disposed in the bore 2| of this sleeve. In order to eilect this telescoping interrelationship between the tube 20 and the sleeve i8, the sleeve must be first unthreaded from the housing, at which time the tube can be inserted therein. The rubber tube has an enlarged or flanged head 22 adapted to seat against a flange 23 on the metal sleeve 2| which resists movement of the tube longitudinally of the sleeve in the direction of the propelled charge. It will also benoted that the housing I0 is recessed at 2l tFig-I ure 1) for accommodating the head 22 so that;

the same can be firmly clamped in position upon the screwing of the sleeve I8 into the housing.

In addition, the sleeve 2| has, its bore, shaped generally complemental to the exterior contour of the tube 20. This bore 2| has a frusta-conical portion 25 terminating in an opening 26. The portion 25 receives; the.- f-ruste-conicalreduced end 2'| of the tube 20 and the opening., 2% receivesthe reduced extremity- 2l of the tube 20. Thus the tube 29- can snugly fit. inside 0E the bore 2:| of sleeve I8,

The conventional air nozzle assembly |9- includes an enlarged head 3d provided with; air passageways- 3| which discharge jets of airl toward the axis of the noszleiordening the shape of the spray. In addition, the sleeve t8, as is well known in the art, is provided with longitudinal air passageways 32-331. These passageways are in communication with an air chamber 35 and a mainpassageway' 36v leading to thepassageway in the nipple; It. Thus air under pressure is delivered from passageway' 36: through passageway 33 to the nozzle passageways 3| and air is also forced, out of the: sleeve through passageways 32 spaced around the center'of. the axis of the nozzle for forcibly aspirating the material being sprayed out of the rubber' tube 22. This use of air forY projecting the material and denning the shape of the spray is well known in the art.

In accordance with time features of my invention the metal tube IB is provided with` a threaded radialY hole 38 in which is threaded a setscrew 31. This` set screw can be adjusted to compress a portion of the tube 2li radially irrwarcl, as shown iny Figure 1, for varying that` erom-sectional area of the bore llil of the tube for varying the rate o! flow of the fluid therethroh.

Also, another feature of thev invention. relates to countersnking the inner end of the bore 40 at 4| to d'ene a seat tor the valve head l5 when i the valve is inclosed pitioxr (as dmwn in Fig'- ure 1).

In theuseofmygimlmonthemtroductionof air through the nipple |.2 into the portion t3 of the gun housing, the rod it is pulled to the right in Figure 1, thus unseating the valve head I5 or in other words, opening the valve.. This permits material to pass from passageway il; into the bore 40 of the rubber tube 20.

At the same time air under preure is delivered through the nipple the main passageway 36, the metal tube I8 and the nozzle head 30. This air acts on the material being delivered to project it forward in the shape of a spray in a manner well known to those familiar with this art.

By reason of the use of my novel rubber tube 20, I nd I am enabled to increase the overall life of the nozzle of the gun since the yieldable material of this tube will resist the abrading action of the material to a greater extent than is true in the case where metal parts are used in contact with the material. The tube may be made of any suitable rubber-like material or a synthetic substitute for the same, depending, of course, on the character of the material being sprayed. For illustration, in spraying some types of material it might be desirable to use a synthetic material such as neoprene, although I have attained excellent results by making the tube from rubber tubular stock.

Furthermore, the yieldable characteristic of the tube enables it to sealingly engage the valve headY |15? when the valve is closed, thus effectively shutting oli the supply of material. In addition, the yieldable characteristic of the material oi' the tube permits the tube to be pre-adjusted for rate of flow by the simple expedient of turning the set screw 31. Also, the tube 20 is easily replaceable when no longer usable.

It will. be understood that modiiicatiom and variationsmay be effected-without departing from the. scope of the novel concepts of the premnt invention.

I claim as my invmtion:

l. In a spray nozzle, a housing provided with anelongated tubular passage, a yieldable tuba of a resilient material of, the class consisting d rubber andsynthetic rubber, said tube boing smuly tted inthe passage with one end positioned to discharge materiali therefrom, a material supply passageway in saidhousing commtmicating with4 the other end of said' tube. a movabie valve cooperable with the other end of the tube to open and close it in communication with said material supply passageway, said other end of said rubber tube: having a counter-sunk valve seat about. the bore of the tube and said valve having a conical-like head cooperable with said countersunk seat whereby said other end of said tubo resiliently engages said valve head with the valve in closed position.

2. In a spray nozzle, a housing provided' with an elongated tubularpassage and` having 'walls dening an airchamber adjacent one endI of said elongated tubular passage, a yieldable tube of a resilient material of the clam consisting of rubber and synthetic rubber, said tube being snugly fitted in the passage withv one end positioned to discharge material therefrom, and a material supply passageway in said housing communica# ing with the other end of said tube. said housing having means adjustably bearing against said tube for displacing a portion of the tube to vary the cross-section. of the bore of the tube and thereby to vary the rate of discharge o! material therefrom, said portion of they tube engaged by said adjustable means, being adjacent a reduced discharge end of the tube, said reduced discharge end of said tube extending beyond said one discharge end of said elongated tubular passage and into said air chamber in spaced relation to said wallsof said housing dening said air chamber.

3. In. a spray nozzle, a housing provided with an elongated tubular passage, a yieldable tube of a rilient material of the class consisting of rubber and synthetic rubber, said tube being snugly tted in the passage with one end positioned to discharge material therefrom, a material supply passageway in said housing communicating with the other end of said tube, a movable valve cooperable with the other end of said tube to open and close it in communication with said material supply passageway, said other end of said tube a coimtersunk valve seat about the bore of the tube, and said valve having a conical head cooperable with said countersunk seat ywhereby said other end of said tube resiliently engages said valve head when the valve is in closed position, said other tube end having an annular flanged head surrounding said countersunk valve seat, and said housing having a recess in which said anged head is seated and a shoulder for abutting the head to prevent endwise displacement of the tube under the pressure of material owing therethrough.

LESLIE W. SMITH.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Re. 23,064 Tirrell Dec. 14, 1948 Number Name Date Zucker Feb. 28, Wadsworth Feb. 8, Swann Dec. 9, Jackson June 28, Tracy May 15, Downs Jan. 7, Brown et a1. Dec. 22, Howard July 27, Rasmussen Apr. 30, Creamer May 31, Luce Nov. 22, Anderson Feb. 27, 

